1. Field of the Invention
The invention relates to an assembly for connecting an external cylindrical part or member having a cylindrical opening to an inner structural part having a cylindrical outer surface, in which the inner structural part is arranged concentrically in the opening of the external part. More particularly, the external structural part is a hub and the internal structural part is a shaft. In the connecting assembly, axially acting locking bolts tension a tapered ring into engagement with a conically surfaced hub. A plurality of wedge segments are arranged between the tapered ring and a counter-support which is circumferentially arranged on the hub. These wedge segments exert axial pressure on the tapered ring to release the conically surfaced hub from engagement with the ring.
2. Description of the Relevant Art
Shaft fastening assemblies of this general type are known in a number of patents. In French Pat. No. 1,361,776 the hub itself carries the external conical circumferential surface. In German Pat. No. 2441400, a ring with an outer conical surface is seated in a cylindrical hub having an inner conical surface, and the inner conical surface of the hub cooperates with the outer conical surface of the ring. Finally, in the disclosure of German Pat. No. 77 18 439 a cylindrical hub is surrounded by a cone ring having two opposingly inclined conical surfaces, which copperate with two outer conical rings.
The general problem in hub and shaft arrangements is to lock the hub and shaft in a manner allowing transmission of an adequate torque through the assembly. For this purpose, the hub must be compressed annularly on the shaft. Generally the compression is applied by means of lock bolts, which act to axially displace the external tapered ring, and thereby produce forces acting radially through the cone of the tapered ring against the inner structural part or shaft. A portion of these forces are, however, consumed in the deformation of the hub and are not available for the generation of clamping forces.
In order to adequately fix the hub to the shaft, the outer tapered rings must be subjected to very high stress. The greatest radial forces are generated when self-retaining cone angles are used. In these assemblies, the outer tapered ring is seated with extraordinary force after locking in engagement with the conical surface of the hub. It is conventional in assemblies of this type to use axial release bolts to unlock the tapered rings. The release bolts apply an axial force in the opposite direction on the tapered ring following the release of the lock bolts, thereby moving it off and conical surface of the hub. The stronger the force seating the tapered ring, the more axial release bolts must be provided. These release bolts are located between the lock bolts and occupy space that is not available for the lock bolts. The requirement of releasability is thus gained at the expense of placing the maximum number of lock bolts over the circumference and generating of a maximum in transferable torque.
Axial displacement of the tapered rings employing conical locking arrangements by means of a further taper arrangement is known per se from German OS No. 25 14 313. As disclosed in that reference, the additional clamping arrangement serves merely to secure the hub on the shaft. In the present invention, axial lock bolts serve this purpose. German reference No. 25 14 313 discloses self-retaining angles on the conical surface which provide the clamping action, but it is not apparent from the disclosure how the existing clamping arrangement may be released.